Sen. Byron Dorgan (D-N.D.) introduced his amendment to the healthcare bill on Tuesday with the support of 19 other senators, including four Republicans, setting up a vote Wednesday.

“U.S. consumers are charged the highest prices in the world for FDA-approved prescription drugs, and that’s just not fair,” Dorgan said in a statement.

But the Obama administration’s declaration on the eve of the vote could derail the amendment despite the fact that Obama co-sponsored Dorgan’s drug imports bill while a member of the Senate and that White House Chief of Staff Rahm Emanuel was a vocal proponent of the House version of the bill when he served as a member of the lower chamber.

The Dorgan amendment “as currently written, the resulting structure would be logistically challenging to implement and resource intensive. In addition, there are significant safety concerns,” Hamburg wrote in a letter to Sen. Sam Brownback (R-Kan.), related to preventing counterfeit or mislabeled medicines from being sold in U.S. pharmacies.

“We commend the sponsors for their efforts to include numerous protective measures in the bill that address the inherent risks of importing foreign products and other safety concerns relating to the distribution system for drugs within the U.S.,” Hamburg wrote, while emphasizing the legislation does not achieve those objectives.

Speaking on the Senate floor Tuesday evening, Dorgan blasted the FDA letter as “completely bogus” and said, “I’m not surprised. I expected this.”

FDA commissioners and secretaries of Health and Human Services in the George W. Bush and Clinton administrations issued similar warnings when the so-called drug reimportation proposal has come up in the past.

The pharmaceutical industry strongly opposes drug reimportation, citing similar concerns as the FDA.